How to restart the floppy service in Windows NT 3.51

[Chuck(G)]

"Layered" is something that is probably NT-specific (maybe later Windows 9X). For a time (up through W2K) we sold a custom driver layered over the standard NT floppy driver that provided support for low-level control of floppy drives. This was mostly sold to embroidery software outfits who needed to support various old floppy formats. Basically, it inserts itself between the Windows API and the kernel-mode device driver and is essentially a duplicate of the logic in the floppy driver, but with a set of APIs all its own.

So what I'm suggesting is that you should take the floppy.sys source and see if there's an IRP that will do the job, then write a layer to issue it. As I said, this has been nearly 30 years from NT 3.51, so I may not remember much.

[Krille]

Any thought on how to get around this?

I guess you could try playing with the permissions on the registry key? Could be a bit dangerous though.

[alank2]

It seems like NT had different starting classes like "boot" or "system" for drivers to determine when (and possibly when) they could load and whether they could (or not) be unloaded.

[Chuck(G)]

I had a look at my NT 4.0 code that I happened to have at hand. I think that you can use a layered device drive to hook the callback from IoQueryDeviceDescription() to alter the BIOS parameters. I don't know if 3.51 implemented PnP, but if so, there's a similar callback for that.

My recollection was that a custom floppy driver for NT was a monstrosity, with over 5K lines of C.